Magnetic memory device

ABSTRACT

A magnetic memory device is provided. The magnetic memory device includes an invariable pinning pattern and a variable pinning pattern on a substrate. A tunnel barrier pattern is interposed between the invariable pinning pattern and the variable pinning pattern, and the pinned pattern is interposed between the invariable pinning pattern and the tunnel barrier pattern. A storage free pattern is interposed between the tunnel barrier pattern and the variable pinning pattern, and a guide free pattern is interposed between the storage free pattern and the variable pinning pattern. A free reversing pattern is interposed between the storage and guide free patterns. The free reversing pattern reverses a magnetization direction of the storage free pattern and a magnetization direction of the guide free pattern in the opposite directions.

The present application is a divisional of and claims priority from U.S.patent application Ser. No. 11/465,075, filed Aug. 16, 2006, now U.S.Pat. No. 7,732,222 which claims the benefit of Korean Patent ApplicationNo. 2005-74937, filed on Aug. 16, 2005, the disclosures of which arehereby incorporated by reference herein in their entireties.

FIELD OF THE INVENTION

The present invention relates to a semiconductor device and a method offorming the same, and particularly, to a magnetic memory device and amethod fabricating the same.

DESCRIPTION OF THE RELATED ART

Generally, a magnetic memory device includes two magnetic substances anda magnetic tunnel junction (MTJ) pattern including an insulating layerinterposed between the two magnetic substances. The magnetic tunneljunction pattern has electric resistance varying according tomagnetization directions of the two magnetic substances. The resistancein the case where the magnetization directions of the two magneticsubstances are equal to each other is greater than the resistance in thecase where the magnetization directions of the two magnetic substancesare opposite to each other. Thus, it can be determined whetherinformation stored in the magnetic memory device is logic “1” or logic“0” by using a voltage drop and/or a change in current amount due tosuch variations in resistance. The magnetic memory device is widely usedbecause of its high speed operation, almost infinite rewritability, andnon-volatility.

In general, a well-known magnetic memory cell may be programmed bymagnetic fields generated from a bit line and a digit line thatintersect each other. Such a magnetic memory device will now bedescribed with reference to accompanying drawing.

FIG. 1 is a cross-sectional view of a conventional magnetic memorydevice.

Referring to FIG. 1, a lower interlayer oxide layer 2 is disposed on asemiconductor substrate 1, and a digit line 3 is disposed on the lowerinterlayer oxide layer 2. Although not shown, a MOS transistor isdisposed between the lower interlayer oxide layer 2 and thesemiconductor substrate 1.

An intermediate interlayer oxide layer 4 covering the digit line 3 andthe lower interlayer oxide layer 2 is disposed on the semiconductorsubstrate 1. A lower contact plug 5 is disposed adjacent to one side ofthe digit line 3 to pass through the intermediate and lower interlayeroxide layers 4 and 2 and contact with the semiconductor substrate 1. Thelower contact plug 5 is laterally spaced apart from the digit line 3.The lower contact plug 5 is electrically connected to source/drainregions of the MOS transistor (not shown).

A lower electrode 6 is disposed on the intermediate interlayer oxidelayer 4. The lower electrode 6 is electrically connected to the lowercontact plug 5, and extends laterally over the digit line 3. The digitline 3 and the lower electrode 6 are insulated from each other by theintermediate interlayer oxide layer 4.

A magnetic tunnel junction pattern 11 is disposed on the lower electrode6. The magnetic tunnel junction pattern 11 includes a pinning layer 7, apinned layer 8, an insulating layer 9, and a free layer 10, which aresequentially stacked. A magnetization direction of the pinned layer 8 ispinned in one direction by the pinning layer 7, and the magnetizationdirection of the free layer 10 may be varied. The magnetic tunneljunction pattern 11 is aligned to overlie the digit line 3.

An upper interlayer oxide layer 12 covers the lower electrode 6 and themagnetic tunnel junction pattern 11, A bit line 14 is disposed on theupper interlayer oxide layer 12 to intersect the digit line 3. The bitline 14 is electrically connected to the magnetic tunnel junctionpattern 11 via an upper contact plug 13 passing through the upperinterlayer oxide layer 12. The bit line 14 is aligned to overlap themagnetic tunnel junction pattern 11. That is, the magnetic tunneljunction pattern 11 is disposed at a spot where the digit line 3 and thebit line 14 intersect, and is interposed between the digit line 3 andthe bit line 14.

To program data in the conventional magnetic memory device, a programvoltage is applied to the bit line 14 and the digit line 3. Accordingly,a first magnetic field is generated around the digit line 3, and asecond magnetic field is generated around the bit line 14. A magneticfield produced by vector production of the first and second magneticfields is selectively applied to the magnetic tunnel junction pattern11. Accordingly, the magnetization direction of the free layer 10included in the magnetic tunnel junction pattern 11 is changed. Here,the magnetization direction of the pinned layer 8 is pinned by thepinning layer 7. As a result, the free layer 10 and the pinned layer 8may have the same magnetization direction or the opposite magnetizationdirections. In this manner, the magnetic tunnel junction pattern 11 maystore data of logic “1” or logic “0”.

The alignment between the bit line 4, the digit line 3, and the magnetictunnel junction pattern 11 is crucial to selectively applying a constantmagnetic field to the magnetic tunnel junction pattern 11 of theconventional magnetic memory device. For this reason, the alignmentbetween the digit line 3 and the magnetic tunnel junction pattern 11,and the alignment between the magnetic tunnel junction pattern 11 andthe bit line 14 are very carefully performed. As a result, a process offabricating the magnetic memory device may become very difficult andcomplicated. Also, the high integration of the magnetic memory devicecannot be easily achieved because sufficient alignment margins should besecured due to the several alignment operations.

Also, peripheral circuits are needed to drive the digit line 3, therebymaking it more difficult to fabricate a highly integrated magneticmemory device. Also, because a program voltage through the digit line 3is required during a program operation, the magnetic memory deviceincreases power consumption.

In addition, the digit line 3 should be disposed under the magnetictunnel junction pattern 11. Thus, the lower contact plug 5 laterallyspaced apart from the magnetic tunnel junction pattern 11 is needed tosecure a path of a current flowing through the magnetic tunnel junctionpattern 11. As a result, a planar area of a magnetic memory cell may beextended.

Further, if the planar area of the free layer 10 is reduced to effecthigh integration of a semiconductor device, data stored in layer 10 maybe lost due to a super-paramagnetic limit. For this reason, it may notbe easy to reduce the planar area of the free layer 10, whichconsequently makes it more difficult to achieve dense integration of themagnetic memory device.

Accordingly, a need remains for a magnetic memory device and a method offabricating the same capable of solving the aforementioned problems andother problems.

SUMMARY OF THE INVENTION

The present invention provides a magnetic memory device optimized forhigh integration and a method of fabricating the same.

Further, the present invention provides a magnetic memory device capableof reducing power consumption and a method of fabricating the same.

Embodiments of the present invention provide a magnetic memory deviceincluding an invariable pinning pattern and a variable pinning patternon a substrate. The term “pattern” as used herein refers to one or morepatterned layers. A tunnel barrier pattern is interposed between theinvariable pinning pattern and the variable pinning pattern, and apinned pattern is interposed between the invariable pinning pattern andthe tunnel barrier pattern. The pinned pattern has a magnetizationdirection pinned by the invariable pinning pattern. A storage freepattern is interposed between the tunnel barrier pattern and thevariable pinning pattern, and a guide free pattern is interposed betweenthe storage free pattern and the variable pinning pattern. A freereversing pattern is interposed between the storage and guide freepatterns. The free reversing pattern reverses a magnetization directionof the storage free pattern and a magnetization direction of the guidefree pattern in the opposite directions.

In some embodiments, the device may further include a high resistancepattern contacting the variable pinning pattern. Here, the variablepinning pattern includes a first surface contacting with the guide freepattern, and a second surface opposite to the first surface. The highresistance pattern contacts the second surface of the variable pinningpattern.

In other embodiments of the present invention, the invariable pinningpattern may pin a magnetization direction of the pinned pattern during aread operation and a program operation. Also, the variable pinningpattern may pin a magnetization direction of the guide free patternduring the read operation, but may not pin the magnetization directionof the guide free pattern during the program operation. A maximumtemperature at which a magnetization pinning force of the invariablepinning pattern is maintained may be higher than a maximum temperatureat which a Magnetization pinning force of the variable pinning patternis maintained. The invariable pinning pattern may be formed of a firstantiferromagnetic substance, and the variable pinning may be formed of asecond antiferromagnetic substance having a blocking temperature lowerthan that of the first antiferromagnetic substance. The blockingtemperature is a maximum temperature at which an exchange coupling forceof an antiferromagnetic substance is maintained, and the exchangecoupling force corresponds to the magnetization pinning force. Theinvariable pinning pattern and the variable pinning pattern may beformed of an antiferromagnetic substance, and the invariable pinningpattern may be thicker than the variable pinning pattern.

In further embodiments, electrons within a first program current mayflow from the invariable pinning pattern to the variable pinningpattern. The first program current arranges in the same direction, amagnetization direction of a portion of the pinned pattern adjacent tothe tunnel barrier pattern and a magnetization direction of the storagefree pattern. And, electrons within a second program current may flowfrom the variable pinning pattern to the invariable pinning pattern. Thesecond program current arranges in the opposite directions, themagnetization direction of a portion of the pinned pattern adjacent tothe tunnel barrier pattern and the magnetization direction of thestorage free pattern.

In other embodiments, the storage free pattern may be thicker than theguide free pattern.

In yet other embodiments, the pinned pattern may include a firstmagnetic pattern; a second magnetic pattern; and a pinned reversingpattern interposed between the first and second magnetic patterns. Thepinned reversing pattern reverses magnetization directions of the firstand second magnetic patterns in the opposite directions. The firstmagnetic pattern contacts with the invariable pinning pattern so thatthe magnetization direction thereof is pinned by the invariable pinningpattern. The magnetization direction of the second magnetic patterns ispinned in the opposite direction to the pinned magnetization directionof the first magnetic pattern by the pinned reversing pattern, and thesecond magnetic pattern contacts with the tunnel barrier pattern.

In further embodiments, the invariable pinning pattern, the pinnedpattern, the tunnel barrier pattern, the storage free pattern, the freereversing pattern, the guide free pattern, and the variable pinningpattern may be stacked sequentially on the substrate. Alternatively, thevariable pinning pattern, the guide free pattern, the free reversingpattern, the storage free pattern, the tunnel barrier pattern, thepinned pattern, and the invariable pinning pattern may be stackedsequentially on the substrate.

In yet further embodiments of the present invention, a method of forminga magnetic memory device include the following operations. An invariablepinning pattern and a variable pinning pattern are formed on asubstrate. A tunnel barrier pattern is formed between the invariablepinning pattern and the variable pinning pattern. A pinned pattern isformed between the invariable pinning pattern and the tunnel barrierpattern, and a magnetization direction of the pinned pattern is pinnedby the invariable pinning pattern. A storage free pattern is formedbetween the tunnel barrier pattern and the variable pinning pattern. Aguide free pattern is formed between the storage free pattern and thevariable pinning pattern. A free reversing pattern is formed between thestorage and guide free patterns. The free reversing pattern reverses amagnetization direction of the storage flee pattern and a magnetizationdirection of the guide free pattern in the opposite directions.

In other embodiments, the method further includes forming a highresistance pattern contacting with the variable pinning pattern. Here,the variable pinning pattern includes a first surface contacting withthe guide free pattern, and a second surface opposite to the firstsurface. The high resistance pattern is formed to contact with thesecond surface of the variable pinning pattern. The invariable pinningpattern may pin a magnetization direction of the pinned pattern during aread operation and a program operation. The variable pinning pattern maypin a magnetization direction of the guide free pattern during the readoperation, and may not pin the magnetization direction of the guide freepattern during the program operation.

The foregoing and other features and advantages of the invention willbecome more readily apparent from the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this application, illustrate embodiment(s) of the invention andtogether with the description serve to explain the principles of theinvention. In the drawings:

FIG. 1 is a cross-sectional view of a conventional magnetic memorydevice;

FIG. 2 is a cross-sectional view of a magnetic memory device accordingto an embodiment of the present invention;

FIGS. 3A and 3B are cross-sectional views illustrating a first programmethod of a magnetic memory device according to an embodiment of thepresent invention;

FIGS. 4A and 4B are cross-sectional views illustrating a second programmethod of a magnetic memory device according to an embodiment of thepresent invention;

FIG. 5 is a cross-sectional view illustrating a modified example of amagnetic memory device according to an embodiment of the presentinvention;

FIGS. 6 through 8 are cross-sectional views illustrating a method offorming a magnetic memory device according to an embodiment of thepresent invention; and

FIG. 9 is a cross-sectional view illustrating a method of forming themagnetic memory device illustrated in FIG. 5.

DETAILED DESCRIPTION

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. However, the present invention is not limited to theembodiments illustrated herein after, and the embodiments herein arerather introduced to provide easy and complete understanding of thescope and spirit of the present invention. In the drawings, thethicknesses of layers and regions are exaggerated for clarity. It willalso be understood that when a layer is referred to as being “on” or“over” another layer or substrate, it can be directly on the other layeror substrate, or intervening layers may also be present. Like referencenumerals in the drawings denote like elements, and thus theirdescription will be omitted.

FIG. 2 is a cross-sectional view illustrating a magnetic memory deviceaccording to an embodiment of the present invention.

Referring to FIG. 2, a lower insulating layer 102 is disposed on asemiconductor substrate 100 (hereinafter, referred to as a substrate),and a lower contact plug 104 passes through the lower insulating layer102 and thus is electrically connected to the substrate 100. The lowerinsulating layer 102 may be formed of a silicon oxide layer, or thelike. The lower contact plug 104 may contain at least one conductivematerial selected from a group consisting of doped polysilicon, metal(e.g., tungsten, molybdenum, etc.), conductive nitride metal (e.g.,titanium nitride, tantalum nitride, etc.) and metal silicide (e.g.,tungsten silicide, cobalt silicide, etc.). The lower contact plug 104may be electrically connected to one source/drain region of a MOStransistor (not shown) formed in the substrate 100 and covered with thelower insulating layer 102. A gate electrode of the MOS transistor isconnected to a word line (not shown) extending in one direction.

A lower electrode 106 a, a magnetic tunnel junction pattern 150 a, andan upper electrode 152 a are sequentially stacked on the lowerinsulating layer 102. The lower electrode 106 a contacts and iselectrically connected to an upper surface of the lower contact plug104. The lower electrode 106 a the magnetic tunnel junction pattern 150a, and the upper electrode 152 a may have sidewalls aligned with respectto one another. Preferably, the lower and upper electrodes 106 a and 152a contain a conductive material having very low reactivity. For example,the lower and upper electrodes 106 a and 152 a may contain titaniumnitride, tantalum nitride, tungsten nitride, or the like.

The magnetic tunnel junction pattern 150 a includes an invariablepinning pattern 110 a and a variable pinning pattern 140 a. A tunnelbarrier pattern 120 a is interposed between the invariable pinningpattern 110 a and the variable pinning pattern 140 a. A pinned pattern115 a is interposed between the invariable pinning pattern 110 a and thetunnel barrier pattern 120 a. The invariable pinning pattern 110 a pinsthe magnetization direction of the pinned pattern 115 a, and the pinnedpattern 115 a contacts with the invariable pinning pattern 110 a and thetunnel barrier pattern 120 a.

The pinned pattern 115 a contains a magnetic substance, and amagnetization direction of the pinned pattern 115 a is pinned by theinvariable pinning pattern 110 a. The pinned pattern 115 a preferablycontains a ferromagnetic substance. The magnetization direction ispinned in one direction at a portion of the pinned pattern 115 aadjacent to the tunnel barrier pattern 120 a. The entire area of thepinned pattern may be formed of one ferromagnetic substance. In thiscase, the magnetization direction of the entire area of the pinnedpattern 115 a is pinned in one direction. Alternatively, at the portionof the pinned pattern 115 a adjacent to the invariable pinning pattern110 a, the magnetization direction may be pinned in the oppositedirection to the magnetization direction of its portion adjacent to thetunnel barrier pattern 120 a.

The tunnel barrier pattern 120 a is formed of an insulating material.For example, the tunnel barrier pattern 120 a may be formed of aluminumoxide, magnesium oxide, etc. The tunnel barrier pattern 120 a preferablyhas a thickness small enough to allow tunneling of electrons. Forexample, the tunnel barrier pattern 120 a may be formed with a thicknessof a few to tens of angstroms.

A storage free pattern 125 a is interposed between the tunnel barrierpattern 120 a and the variable pinning pattern 140 a. The storage freepattern 125 a preferably contacts with the tunnel barrier pattern 120 a.A guide free pattern 135 a is interposed between the storage freepattern 125 a and the variable pinning pattern 140 a. Preferably, theguide free pattern 135 a contacts the variable pinning pattern 140 a. Afree reversing pattern 130 a is interposed between the storage freepattern 125 a and the guide free pattern 135 a. The free reversingpattern 130 a has two opposite first and second surfaces, and the firstand second surfaces of the free reversing pattern 130 a contact with thestorage free pattern 125 a and the guide free pattern 135 a,respectively.

Preferably, the storage free pattern 125 a is thicker than the guidefree pattern 135 a. The storage and guide free patterns 125 a and 135 acontain magnetic substances. Particularly, the storage and guide freepatterns 125 a and 135 a preferably contain ferromagnetic substances.

For example, the storage and guide patterns 125 a and 135 a each mayinclude at least one ferromagnetic material selected from the groupconsisting of Fe, Co, Ni, Gd, Dy, MnAs, MnBi, MnSb, CrO2, MnOFe2O3,FeOFe2O3, NiOFe2O3, CuOFe2O3, MgOFe2O3, EuO, Y3Fe5O12, etc. Besides, thestorage and guide free patterns 125 a and 135 a may be formed of amaterial made by adding boron (B) to the ferromagnetic substance. Boronmay make a ferromagnetic substrate amorphous. The storage and guidepatterns 125 a and 135 a may be formed of different ferromagneticsubstances or of the same ferromagnetic substance.

The magnetization direction of the storage free pattern 125 a may bevaried. The resistance of the magnetic tunnel junction pattern 150 a isvaried according to the magnetization direction of the storage freepattern 125 a. That is, a first resistance value in the case where themagnetization directions of the storage free pattern 125 a and of aportion of the pinned pattern 115 a adjacent to the tunnel barrierpattern 120 are arranged in the same direction is smaller than a secondresistance value in the case where the magnetization directions thereofare opposite to each other. The magnetic tunnel junction pattern 150 astores data of logic “1” or logic “0” according to the resistancevalues.

The free reversing pattern 130 a has a magnetization reversing forcethat reverses the magnetization directions of the storage free pattern125 a and the guide free pattern 135 in the opposite directions.Accordingly, the magnetization direction of the guide free pattern 135 aand the magnetization direction of the storage free pattern 125 a arearranged in the opposite directions by the free reversing pattern 130 a.The free reversing pattern 130 a is preferably formed of a conductivematerial having the magnetization reversing force. For example, the freereversing pattern 130 a may contain ruthenium (Ru), iridium (Ir),rhodium (Rh), etc. As the magnetization direction of the storage freepattern 125 a is changed, the magnetization direction of the guide freepattern 135 a is also changed. Also, the magnetization direction of theguide free pattern 135 a may be pinned by the variable pinning pattern140 a under predetermined conditions.

The variable pinning pattern 140 a pins the magnetization direction ofthe guide free pattern 135 a during a read operation of a magneticmemory cell. The variable pinning pattern 140 a does not pin themagnetization direction of the guide free pattern 135 a during a programoperation of the magnetic memory cell. Also, the invariable pinningpattern 110 a pins the magnetization direction of the pinned pattern 115a during both read and program operations.

The invariable pinning pattern 110 a has a magnetization pinning forcethat pins the magnetization direction of the pinned pattern 115 a. Underpredetermined conditions, the variable pinning pattern 140 a has amagnetization pinning force that pins the magnetization direction of theguide free pattern 135 a. The magnetization pinning force is defined asa force pinning a magnetization direction of an adjacent magneticsubstance.

Preferably, a first maximum temperature at which the magnetizationpinning force of the invariable pinning pattern 110 a is higher than asecond maximum temperature at which the magnetization pinning force ofthe variable pinning pattern 140 a is maintained. The properties of theinvariable pinning and variable pinning patterns 110 a and 140 a may beobtained by using differences in the maximum temperatures at which themagnetization pinning forces are maintained.

Heat of a program temperature is supplied to the magnetic tunneljunction pattern 150 a during the program operation. Here, the programtemperature is preferably between the first maximum temperature and thesecond maximum temperature. Accordingly, during the program operation,the invariable pinning pattern 110 a maintains a magnetization pinningforce while the variable pinning pattern 140 a loses the magnetizationpinning force. As a result, during the program operation, the invariablepinning pattern 110 a pins the magnetization direction of the pinnedpattern 115 a while the variable pinning pattern 140 a does not pin themagnetization direction of the guide free pattern 135 a. Because heat ofthe program temperature is not supplied during the read operation, bothinvariable pinning and variable pinning patterns 110 a and the 140 amaintain the magnetization pinning forces, thereby pinning themagnetization directions of the pinned pattern 115 a and the guide freepattern 135 a, respectively.

Preferably, the invariable pinning and variable pinning patterns 110 aand 140 a are formed of an antiferromagnetic substance. Here,preferably, the invariable pinning pattern 110 a is formed of a firstantiferromagnetic substance, and the variable pinning pattern 140 a isformed of a second antiferromagnetic substance having a lower blockingtemperature than that of the first antiferromagnetic substance. Theblocking temperature is a maximum temperature at which an exchangecoupling force of an antiferromagnetic substance can be maintained. Theexchange coupling force pins a magnetization direction of a magneticsubstances contacting with an antiferroinagnetic substance andcorresponds to the magnetization pinning force.

The blocking temperature of platinum manganese (PtMn) is higher than theblocking temperatures of iridium manganese (IrMn), and iron manganese(FeMn). Also, the blocking temperature of IrMn is higher than that ofthe FeMn. Accordingly, for example, the invariable pinning pattern 110 amay be formed of PtMn, and the variable pinning pattern 140 a may beformed of IrMn or FeMn. Also, the invariable pinning pattern 110 a andthe variable pinning pattern 140 a may be formed of IrMn and FeMn,respectively. Of course, the invariable pinning pattern 110 a may beformed of a different antiferromagnetic substance, and the variablepinning pattern 110 a may be formed of another differentantiferromagnetic substance having a blocking temperature lower thanthat of the invariable pinning pattern 110 a.

An antiferromagnetic layer may change in the blocking temperatureaccording to its thickness. Using this property, the invariable pinningpattern 110 a may be formed thicker than the variable pinning pattern140 while the invariable pinning and variable pinning patterns 110 a and140 a are formed of an antiferromagnetic substance. Accordingly, theblocking temperature of the invariable pinning pattern 110 a is higherthan the blocking temperature of the variable pinning pattern 140 a.

Besides, the invariable pinning pattern 110 a and the variable pinningpattern 140 a may be formed by using antiferromagnetic substances havingdifferent blocking temperatures and using changes in blockingtemperature according to the thickness of an antiferromagnetic substance(i.e., the blocking temperature increases as the thickness is greater).In other words, the invariable pinning pattern 110 a is formed of afirst antiferromagnetic substance, and the variable pinning pattern 140a is formed of a second antiferromagnetic substance having a blockingtemperature lower than that of the first antiferromagnetic substance.The first antiferromagnetic substance may be formed thicker than thesecond antiferromagnetic substance.

As described above, the free reversing pattern 130 a has a magnetizationreversing force. Here, the maximum temperature at which themagnetization reversing force of the free reversing pattern 130 a ismaintained is preferably higher than the program temperature.Accordingly, the magnetization reversing force of the free reversingpattern 130 a is maintained during the program operation to therebychange the magnetization direction of the storage free pattern 125 a,and thus the magnetization direction of the guide free pattern 135 a isreversed to be opposite to the magnetization direction of the storagefree pattern 125 a. Particularly, the maximum temperature at which themagnetization reversing force of the free reversing pattern 130 a ismaintained may be higher than the first maximum temperature of theinvariable pinning pattern 110 a.

The pinned pattern 115 a may include a first magnetic pattern 111 a, asecond magnetic pattern 113 a, and a pinned reversing pattern 112 ainterposed between the first and second magnetic patterns 111 a and 113a. Preferably, the first magnetic pattern 111 a contacts with theinvariable pinning pattern 110 a, and the second magnetic pattern 113 acontacts with the tunnel barrier pattern 120 a. The pinned reversingpattern 112 a contacts with the first and second magnetic patterns 111 aand 113 a.

The magnetization direction of the first magnetic pattern 111 a ispinned by the invariable pinning pattern 120 a. The magnetizationdirection of the first magnetization pattern 111 a is pinned by theinvariable pinning pattern 120 during both read and program operations.The pinned reversing pattern 112 a reverses the magnetization directionsof the first and second magnetic patterns 111 a and 113 a in theopposite directions. Accordingly, the magnetization direction of thesecond magnetic pattern 113 a is pinned in the opposite direction to themagnetization direction of the first magnetic pattern 111 a by thepinned reversing pattern 112 a. The magnetization direction of thesecond magnetic pattern 113 a is pinned during both read and programoperations.

Preferably, the first and second magnetic patterns 111 a and 113 a areformed of a ferromagnetic substance. For example, the first and secondmagnetic patterns 111 a and 113 a may be formed of at least oneferromagnetic substance selected from the group consisting of Fe, Co,Ni, Gd, Dy, MnAs, MnBi, MnSb, CrO2, MnOFe2O3, FeOFe2O3, NiOFe2O3,CuOFe2O3, MgOFe203, EuO, Y3Fe5O12, etc. Besides, the first and secondmagnetic patterns 111 a and 113 a may be formed of a material made byadding boron (B) to the ferromagnetic substance. The first and secondmagnetic patterns 111 a and 113 a may be formed of the same material orof different materials. The pinned reversing pattern 112 a is preferablyformed of a conductive material having a magnetization reversing force.For example, the pinned reversing pattern 112 a may contain ruthenium(Ru), iridium (Ir), rhodium (Rh), etc.

The variable pinning pattern 140 a has a first surface contacting theguide free pattern 135 a and a second surface opposite to the firstsurface. Here, the magnetic tunnel junction pattern 150 a may furtherinclude a high resistance pattern 145 a contacting the second surface ofthe variable pinning pattern 140 a. The high resistance pattern 145 a isformed of a material with high resistance. Predetermined currents mayflow through the high resistant pattern 145 a. For example, the highresistance pattern 145 a may be formed of a material containing oxygenand material elements contained in the variable pinning pattern 140 a.That is, the high resistance pattern 145 a may be formed by oxidizingthe surface of the variable pinning pattern 145 a. Of course, the highvoltage pattern 145 a may be formed of a different high resistancematerial. Preferably, the high resistance pattern 145 has a very thinthickness of a few to tens of angstroms.

Referring to FIG. 2, the lowermost portion of the magnetic tunneljunction pattern 150 a may be the invariable pinning pattern 110 a, andthe uppermost portion of the magnetic tunnel junction pattern 150 a maybe the high resistance pattern 140 a. That is, the invariable pinningpattern 110 a, the pinned pattern 115 a, the tunnel barrier pattern 120a, the storage free pattern 125 a, the free reversing pattern 130 a, theguide free pattern 135 a, the variable pinning pattern 140 a, and thehigh resistance pattern 145 a may be sequentially stacked on the lowerelectrode 106 a. In this case, the invariable pinning pattern 110 a iselectrically connected to the lower contact plug 104 via the lowerelectrode 106 a, and the variable pinning pattern 140 a is electricallyconnected to the upper electrode 152 a via the high resistance pattern145 a. The lower electrode 106 a may restrict a reaction between theinvariable pinning pattern 110 a and the lower insulating layer 102, andthe upper electrode 152 a may protect the high resistance pattern 145 a.If the high resistance pattern 145 a is omitted, the upper electrode 152a may contact with the variable pinning pattern 140 a.

An upper insulating layer 154 covers an entire surface of the substrate100. The upper insulating layer 154 covers the lower insulating layer102, the lower electrode 106 a, the magnetic tunnel junction pattern 150a, and the upper electrode 152 a. The upper insulating layer 154 may beformed of a silicon oxide layer.

An upper contact plug 158 fills a contact hole 156 passing through theupper insulating layer 154 and exposing the upper electrode 152 a. Aline 160 contacting with the upper contact plug 158 is disposed on theupper insulating layer 154. The line 160 is electrically connected tothe magnetic tunnel junction pattern 150 a via the upper contact plug158 and the upper electrode 152 a. The line 160 corresponds to a bitline. The line 160 may be disposed across the word line (not shown).

The upper contact plug 158 may be omitted, and the line 160 may extenddownward to fill the contact hole 156. Alternatively, an upper surfaceof the upper insulating layer 154 may be flattened as high as an uppersurface of the upper electrode 152 a to expose the upper electrode 152a, and the line 160 may contact directly the exposed upper electrode 152a.

The upper contact plug 158 and the line 160 contain a conductivematerial. For example, the upper contact plug 158 and the line 160 eachmay contain at least one conductive material selected from the groupconsisting of doped polysilicon, metal (e.g., tungsten, molybdenum,etc.), conductive nitride metal (e.g., titanium nitride, tantalumnitride, etc.) and metal silicide (e.g., tungsten silicide, cobaltsilicide, etc.). The upper contact plug 158 and the line 160 may beformed of the same conductive material or of different conductivematerials.

A program operation with respect to the magnetic memory device havingthe aforedescribed structure may be divided into a first programoperation and a second program operation. The first program operation isdefined as an operation of arranging in the same direction, amagnetization direction of a portion of the pinned pattern 110 aadjacent to the tunnel barrier pattern 120 a and a magnetizationdirection of the storage free pattern 125 a. That is, the first programoperation corresponds to an operation of converting a state of themagnetic tunnel junction pattern 150 a into a low resistance state. Thesecond program operation is defined as an operation of arranging inopposite directions, the magnetization direction of a portion of thepinned pattern 110 a adjacent to the tunnel barrier pattern 120 a andthe magnetization direction of the storage free pattern 125 a. That is,the second program operation corresponds to an operation of converting astate of the magnetic tunnel junction pattern 150 a into a highresistance state. The first and second program operations will now bedescribed with reference to accompanying drawings.

FIGS. 3A and 3B are cross-sectional views for describing the firstprogram method of a magnetic memory device according to an embodiment ofthe present invention.

Referring to FIGS. 3A and 3B, a magnetization direction 170 of a portionof the pinned pattern 115 a adjacent to the tunnel barrier pattern 120 ais pinned in a first direction. A magnetization direction 172 of thestorage free pattern 125 a is arranged in a second direction opposite tothe first direction. Here, a magnetization direction 174 of the guidefree pattern 135 a is arranged in the first direction opposite to themagnetization direction 172 of the storage free pattern 125 a. The firstprogram operation of converting the magnetization direction 172 of thestorage free pattern 125 a into the first direction will now bedescribed.

At the time of the first program operation, a first program current isflowed to the magnetic tunnel junction pattern 150. The flow 180 ofelectrons within the first program current (hereinafter, referred to theflow of first electrons) proceeds to the variable pinning pattern 140 afrom the invariable pinning pattern 110 a. That is, the first programcurrent flows from the variable pinning pattern 140 a to the invariablepinning pattern 110 a. Joule's heat is generated at the tunnel barrierpattern 120 a by the first program current. The Joule's heat correspondsto heat of a program temperature. As described above, the programtemperature is lower than the maximum temperature at which themagnetization pinning force of the invariable pinning pattern 110 a ismaintained, and is higher than the maximum temperature at which themagnetization pinning force of the variable pinning pattern 140 a ismaintained. Accordingly, during the first program operation, theinvariable pinning pattern 110 a maintains the magnetization pinningforce while the variable pinning pattern 140 a loses the magnetizationpinning force. As a result, the invariable pinning pattern 140 a pinsthe magnetization direction of the pinned pattern 115 a but does not pinthe magnetization direction 174 of the guide free pattern 135 a. TheJoule's heat is generated even from the high resistance pattern 145 a.The high resistance pattern 145 a may perform a supplementary role insupplying heat of the program temperature. In this case, the heat of theprogram temperature is supplied by the high resistance pattern 145 a aswell as by the tunnel barrier pattern 120 a. Because of the highresistance pattern 145 a, heat of the program temperature can be moreeasily supplied to the variable pinning pattern 140 a. Of course, evenif the high resistance pattern 145 a is omitted, the tunnel barrierpattern 120 a can still supply heat of the program temperature.

Electrons passing through the pinned pattern 115 a and tunneling throughthe tunnel barrier pattern 120 a by the flow 180 of the first electronsinclude first large-numbered electrons and first small-numberedelectrons. The first large-numbered electrons have spins in the firstdirection identical to the magnetization direction 170 of the pinnedpattern 115 a. The first small-numbered electrons may have spins in thesecond reaction opposite to the magnetization direction 170 of thepinned pattern 115 a. The amount of the first large-numbered electronsis much larger than the amount of the first small-numbered electrons.Thus, a large amount of the first large-numbered electrons exist withinthe storage free pattern 125 a. As a result, the magnetization direction172 (refer to FIG. 3A) of the storage free pattern 125 a is changed tothe first direction identical to the magnetization direction 170 of thepinned pattern 115 a by receiving torque due to the spins of the firstlarge-numbered electrons in the first direction. The magnetizationdirection 172′ of the storage free pattern 125 a, the first direction,is illustrated in FIG. 313.

When the magnetization direction 172, the second direction, of thestorage free pattern 125 a is converted into the magnetization direction172′, the first direction, the magnetization direction 174 (refer toFIG. 3A), the first direction, of the guide free pattern 135 a isconverted into the magnetization direction 174′ (refer to FIG. 3B), thesecond direction. Because the variable pinning pattern 140 a loses themagnetization pinning force at the time of the first program operation,it is possible to change the magnetization direction of the guide freepattern 135 a. The storage free pattern 125 a is thicker than the guidefree pattern 135 a. Accordingly, the conversion of the magnetizationdirection of the storage free pattern 125 a is dominant over theconversion of the magnetization direction of the guide free pattern 135a. As a result, the conversion of the magnetization direction of thestorage free pattern 125 a facilitates the conversion of themagnetization direction of the guide free pattern 135 a.

As illustrated in FIG. 3B, the first program operation allows themagnetization direction 170 of the pinned pattern 115 a and themagnetization direction 172′ of the storage free pattern 125 a to bearranged parallel in the same direction.

Then, the second program operation will now be described with referenceto FIGS. 4A and 4B.

FIGS. 4A and 4B are cross-sectional views for describing a secondprogram method of the magnetic memory device according to an embodimentof the present invention.

Referring to FIGS. 4A and 4B, a second program current is flowed to themagnetic tunnel junction pattern 150 a at the time of the second programoperation. Here, the flow 190 of electrons within the second programcurrent (hereinafter, referred as the flow of second electrons) proceedsfrom the variable pinning pattern 140 a to the invariable pinningpattern 110 a. That is, the second program current flows from theinvariable inning pattern 110 a to the variable pinning pattern 140 a.Heat of the program temperature is generated by the second programcurrent and the tunnel barrier pattern 120 a. Accordingly, the variablepinning pattern 140 a loses a magnetization pinning force while theinvariable pinning pattern 110 a maintains the magnetization pinningforce. Joule's heat is generated at the high voltage pattern 145 to thussupplement heat of the program temperature. Electrons flowing via theguide free pattern 135 a by the flow 190 of the second electrons includesecond large-numbered electrons and second small-numbered electrons. Thesecond large-numbered electrons have spins in the same direction as themagnetization direction 174′ of the guide free pattern 135 a, and thesecond small-numbered electrons have spins in the opposite direction tothe magnetization direction 174′ of the guide free pattern 135 a. Theamount of the second large-numbered electrons is much larger than theamount of the second small-numbered electrons. Accordingly, the secondlarge-numbered electrons having spins in the second direction oppositeto the magnetization direction 170 of the pinned pattern 115 a exist inlarge amount in the storage free pattern 125 a.

Besides, electrons passing through the storage free pattern 125 ainclude third large-numbered electrons and third small-numberedelectrons. The third large-numbered electrons have spins in the samedirection as the magnetization direction 172′ of the storage freepattern 125 a, and the third small-numbered electrons have spins in theopposite direction to the magnetization direction 172′ of the storagefree pattern 125 a. The spins of the third large-numbered electrons arein the same direction as the magnetization direction 170 of the pinnedpattern 115 a. Thus, most of the third large-numbered electrons smoothlypass through the tunnel barrier pattern 120 a and the pinned pattern 115a and flow to the invariable pinning pattern 110 a. In contrast, thethird small-numbered electrons have spins in the opposite direction tothe magnetization direction 170 of the pinned pattern 115 a.Accordingly, most of the third small-numbered electrons cannot smoothlypass through the pinned pattern 115 a but are stored between the pinnedpattern 115 a and the storage free pattern 125 a. The spin direction ofthe third small-numbered electrons is the second direction identical tothe spin direction of the second large-numbered electrons.

Consequently, the magnetization direction 172′ of the storage freepattern 125 a is converted into the second direction because of thesecond large-numbered electrons existing in large amount in the storagefree pattern 125 a and the third small-numbered electrons accumulatedbetween the pinned pattern 115 a and the storage free pattern 125 a.Here, the magnetization direction 174′ of the guide free pattern 135 ais reversed by the free reversing pattern 130 a.

FIG. 4A illustrates that the second program operation allows themagnetization direction 172 of the storage free pattern 125 a to bearranged in the opposite direction to the magnetization direction 170 ofthe pinned pattern 115 a, and allows the magnetization direction 174 ofthe guide free pattern 135 a to be arranged in the opposite direction tothe magnetization direction 172 of the storage free pattern 125 a.

A read operation of the magnetic memory device will now be described.

Preferably, the smaller amount of read current than the amount of thefirst and second program currents is flowed through the magnetic tunneljunction pattern 150 a. Thus, the temperature of heat generated by thetunnel barrier pattern 120 a and the high resistance pattern 145 a dueto the read current becomes lower than the maximum temperature at whicha magnetization pinning force of the variable pinning pattern 140 a ismaintained. As a result, the variable pinning pattern 140 a pins themagnetization direction of the guide free pattern 135 a. The variablepinning pattern 140 a maintains the magnetization pinning force even ina wait state of the magnetic memory device as well as during the readoperation. Because the variable pinning pattern 140 a maintains themagnetization pinning force during the read operation and in the waitstate, a super-paramagnetic limit is overcome even though a planar areaof the magnetic tunnel junction pattern 150 a is reduced, therebyimproving the ability to maintain data of the magnetic tunnel junctionpattern 150 a.

The magnetic memory device of the aforementioned structure does notrequire the conventional digit line. Accordingly, a peripheral circuitrelated to the conventional digit line is not required. Also, anincrease in area of the magnetic memory cell caused by the conventionaldigit line may be prevented. As a result, a highly-integrated magneticmemory device can be implemented.

Also, the fine alignment processes are not needed because theconventional digit line need not be used. Accordingly, the method offabricating the magnetic memory device having the magnetic tunneljunction pattern 150 a is very much facilitated, thereby improvingproductivity.

Furthermore, power consumption related to the conventional digit line isreduced by not requiring the related digit line, so that a magneticmemory device with low power consumption may be implemented.

Besides, the variable pinning pattern 140 a pins the magnetizationdirection of the guide free pattern 135 a during the read operation andin the wait state, and the free reversing pattern 130 a pins themagnetization direction of the storage free pattern 125 a. Thus, asuper-paramagnetic limit is overcome, thereby reducing planar area ofthe magnetic tunnel junction pattern 150 a. As a result, a morehighly-integrated magnetic memory device may be implemented.

As for the electrical connection between the aforementioned magnetictunnel junction pattern 150 a and the line 160, the variable pinningpattern 140 a is electrically connected to the line 160 via the upperelectrode 152 a. Alternatively, the invariable pinning pattern of themagnetic tunnel junction pattern may be electrically connected to theline used as a bit line. This will now be described with reference toaccompanying drawings. In this modified example, like reference numeralsin the drawings denote like elements with those of the aforementionedmagnetic memory device of FIG. 2.

FIG. 5 is a cross-sectional view illustrating the modified example ofthe magnetic memory device according to an embodiment of the presentinvention.

Referring to FIG. 5, a variable pinning pattern 140 a′ is disposed on alower electrode 106 a contacting with a lower contact plug 102. A highresistance pattern 145 a′ may be disposed between the variable pinningpattern 140 a′ and the lower electrode 106 a. A guide free pattern 135a′, a free reversing pattern 130 a′, a storage free pattern 125 a′, atunnel barrier pattern 120 a′, a pinned pattern 115 a′, and aninvariable pinning pattern 110 a′ are sequentially stacked on thevariable pinning pattern 140 a′. The pinned pattern 115 a′ may include afirst magnetic pattern 111 a′ contacting with the invariable pinningpattern 110 a′, a second magnetic pattern 113 a′ contacting with thetunnel barrier pattern 120 a′, and a pinned reversing pattern 112 a′interposed between the first and second magnetic patterns 111 a′ and 113a′. The invariable pinning pattern 110 a′ is connected to an upperelectrode 152 a and is electrically connected to a line 160.

The high voltage pattern 145 a′, the variable pinning pattern 140 a′,the guide free pattern 135 a′, the free reversing pattern 130 a′, thestorage free pattern 125 a′, the tunnel barrier pattern 120 a′, thepinned pattern 115 a′ and the invariable pinning pattern 110 a′, whichare sequentially stacked form a magnetic tunnel junction pattern 150 a′.

Electrons within a first program current used at the time of a firstprogram operation of a magnetic memory device having the aforementionedstructure flow from the invariable pinning pattern 110 a′ to thevariable pinning pattern 140 a′. The first program operation is anoperation of arranging a magnetization direction of the pinned pattern115 a′ and a magnetization direction of the storage free pattern 125 a′in the same direction. Electrons within a second program current used atthe time of a second program operation of the magnetic memory deviceflow from the variable pinning pattern 140 a′ to the invariable pinningpattern 110 a′. Here, the second program operation is an operation ofarranging the magnetization direction of the pinned pattern 115 a′ andthe magnetization direction of the storage free pattern 125 a′ in theopposite directions.

The high voltage pattern 145 a′, the variable pinning pattern 140 a′,the guide free pattern 135 a′, the free reversing pattern 130 a′, thestorage free pattern 125 a′, the tunnel barrier pattern 120 a′, thepinned pattern 115 a′, and the invariable pinning pattern 110 a′ may beformed of the same materials and have the same properties as the highresistance pattern 145 a, the variable pinning pattern 140 a, the guidefree pattern 135 a, the free reversing pattern 130 a, the storage freepattern 125 a, the tunnel barrier pattern 120 a, the pinned pattern 115a, and the invariable pinning pattern 110 a, respectively.

Furthermore, the high resistance pattern 145 a′ may be formed of amaterial containing oxygen and material elements contained in the lowerelectrode 106 a. That is, the high resistance pattern 145 a′ may beformed by oxidizing a surface of the lower electrode 106 a.

The method of forming a magnetic memory device according to anembodiment of the present invention will now be described.

FIGS. 6 through 8 are cross-sectional views for describing a method offorming a magnetic memory device according to an embodiment of thepresent invention.

Referring to FIG. 6, a lower insulating layer 102 is formed on asubstrate 100, and the lower insulating layer 102 is patterned to form acontact hole exposing the substrate 100. A lower contact plug 104 isembedded in the contact hole.

Referring to FIG. 7, a lower conductive layer 106, an invariable pinninglayer 110, a pinned layer 115, a tunnel barrier layer 120, a storagefree layer 125, a free reversing layer 130, a guide free layer 135, avariable pinning layer 140, a high resistance layer 145, and an upperconductive layer 152 are sequentially formed on an entire surface of thesubstrate 100 including the lower contact plug 104. The layers 110, 115,120, 125, 130, 135, 140 and 145 between the lower conductive layer 106and the upper conductive layer 152 form a magnetic tunnel junctionmultilayer 150. The pinned layer 115 may include a first magnetic layer111 contacting with the invariable pinning layer 110, a second magneticlayer 113 contacting with the tunnel barrier layer 120, and a pinnedreversing layer 112 interposed between the first and second magneticlayers 111 and 113.

The high resistance layer 145 may be formed by performing an oxidationprocess on a surface of the variable pinning layer 140. Alternatively,the high resistance layer 145 may be formed of a different highresistance material layer by a chemical vapor deposition (CVD)technology.

Referring to FIG. 8, the upper conductive layer 152, the magnetic tunneljunction multilayer 150, the lower conductive layer 106 are successivelypatterned, thereby forming a lower electrode 106 a, a magnetic tunneljunction pattern 150 a, and an upper electrode 152 a stacked in thesequential order.

The magnetic tunnel junction pattern 150 a includes a invariable pinningpattern 110 a, a pinned pattern 115 a, a tunnel barrier pattern 120 a, astorage free pattern 125 a, a free reversing pattern 130 a, a guide freepattern 135 a, a variable pinning pattern 140 a, and a high resistancepattern 145 a, which are sequentially stacked. The pinned pattern 115 amay include a first magnetic pattern 111 a contacting with the tunnelbarrier pattern 120 a, and a pinned reversing pattern 112 a interposedbetween the first and second magnetic patterns 111 a and 113 a.

Properties of elements contained in the magnetic tunnel junction pattern150 a, and materials forming them are the same as those described withreference to FIG. 2.

An upper insulating layer 154 is formed on an entire surface of thesubstrate 100, and the upper insulating layer 154 is patterned to form acontact hole 156 exposing the upper electrode 152 a.

Then, an upper contact plug 158 of FIG. 2 is embedded in the contacthole 156, and the line 160 of FIG. 2 contacting with the upper contactplug 158 is formed on the upper insulating layer 154, therebyimplementing the magnetic memory device of FIG. 2.

As another method, after the upper insulating layer 154 is flattened orplanarized until the upper electrode 152 a is exposed, the line 160 ofFIG. 2 may be formed to contact with the exposed upper electrode 152 a.In this case, the operation of forming the contact hole 156 and theoperation of forming the upper contact plug 158 are omitted.

The method of forming the magnetic memory device illustrated in FIG. 5will next be described. This is similar to the aforedescribed method offorming the magnetic memory device.

FIG. 9 is a cross-sectional view for describing the method of formingthe magnetic memory device illustrated in FIG. 5.

Referring to FIG. 9, a lower conductive layer 106, a high resistancelayer 145′, a variable pinning layer 140′, a guide free layer 135′, afree reversing layer 130′, a storage free layer 125′, a tunnel barrierlayer 120′, a pinned layer 115′, an invariable pinning layer 110′, andan upper conductive layer 152 are formed sequentially on a substrate 100having a lower contact plug 104.

The high resistance layer 145′ may be formed by oxidizing a surface ofthe lower conductive layer 106. Alternatively, the high resistance layer145′ may be formed by forming on the lower conductive layer 106, amaterial layer formed of the same material as the variable pinning layer140′ at a thickness of a few to tens of angstroms, and oxidizing thematerial layer. Alternatively, the high resistance layer 145′ may beformed of a different material layer having high resistance by achemical vapor deposition technology.

The pinned layer 115′ may include a first magnetic layer 111′ contactingwith the invariable pinning layer 110′, the second magnetic layer 113′contacting with the tunnel barrier layer 120′, and a pinned reversinglayer 112′ interposed between the first and second magnetic layers 111′and 113′.

The layers 145′, 140′, 135′, 130′, 125′, 120′, 115′ and 110′ between thelower conductive layer 106 and the upper conductive layer 152 form amagnetic tunnel junction multilayer 150′.

The upper conductive layer 152, the magnetic tunnel junction multilayer150′, and the lower conductive layer 106 are successively patterned,thereby forming a lower electrode 106, a magnetic tunnel junctionpattern 150 a′, and an upper electrode 152 a that are stacked in thesequential order illustrated in FIG. 5.

Subsequent processes may be performed in the same manner as describedwith reference to FIG. 8. Thus, the magnetic memory device of FIG. 5 maybe implemented.

According to the present invention, a magnetic direction of a storagefree pattern is arranged in the same direction as a magnetizationdirection of a pinned pattern by electrons within a program currentflowing through the pinned pattern, and is arranged in the oppositedirection to the magnetization direction of the pinned pattern byelectrons within a program current flowing through a guide free pattern.That is, the magnetic memory device according to the present inventiondoes not require the conventional digit line. As a result, an increasein a cell area due to the conventional digit line can be prevented, andperipheral circuits for driving the digit line can be removed, therebymaking it possible to implement a highly integrated magnetic memorydevice. Also, fine alignment processes used to form the digit line canbe omitted, thereby very much simplifying the method of forming themagnetic memory device and thus improving the productivity. Furthermore,power consumption required to drive the related digit line can beremoved, so that a magnetic memory device with low power consumption maybe implemented.

Also, a magnetization direction of a guide free pattern is not pinned bythe variable pinning pattern at the time of a program operation, and ispinned by the variable pinning pattern at the time of a read operation.Accordingly, a magnetization direction of a storage free pattern storingdata is pinned in every state (e.g., a reading operation, a wait state,etc.) excluding the program operation by the variable pinning pattern,the guide free pattern, and a free reversing pattern. As a result, asuper-paramagnetic limit is overcome, and thus the planar area of amagnetic tunnel junction pattern can be reduced, so that a more highlyintegrated magnetic memory device can be implemented.

Having described the principles of the invention in differentembodiments, it will be apparent to those skilled in the art thatvarious modifications and variations can be made in the presentinvention without departing from such principles. Thus, it is intendedthat the present invention covers the modifications and variations ofthis invention provided they come within the scope of the appendedclaims and their equivalents.

1. A magnetic memory device comprising: an invariable pinning patternand a variable pinning pattern on a substrate; a tunnel barrier patternbetween the invariable pinning pattern and the variable pinning pattern;a pinned pattern between the invariable pinning pattern and the tunnelbarrier pattern, the pinned pattern configured to have a magnetizationdirection pinned by the invariable pinning pattern; a storage freepattern between the tunnel barrier pattern and the variable pinningpattern; a guide free pattern between the storage free pattern and thevariable pinning pattern, wherein the variable pinning pattern has afirst surface contacting the guide free pattern and a second surfaceopposite the first surface; a high resistance pattern contacting thesecond surface of the variable pinning pattern and including oxygen andelements included in the variable pinning pattern; and a free reversingpattern between the storage and guide free patterns, the free reversingpattern being configured to reverse a magnetization direction of thestorage free pattern and a magnetization direction of the guide freepattern in opposite directions.
 2. The device of claim 1, wherein theinvariable pinning pattern is configured to pin a magnetizationdirection of the pinned pattern during a read operation and a programoperation, and the variable pinning pattern is configured to pin amagnetization direction of the guide free pattern during the readoperation, the variable pinning pattern further configured not to pinthe magnetization direction of the guide free pattern during the programoperation.
 3. The device of claim 1, wherein electrons within a firstprogram current flow from the invariable pinning pattern to the variablepinning pattern, and the first program current arranges a magnetizationdirection of a portion of the pinned pattern adjacent to the tunnelbarrier pattern and a magnetization direction of the storage freepattern in a same direction; and wherein electrons within a secondprogram current flow from the variable pinning pattern to the invariablepinning pattern, and the second program current arranges themagnetization direction of a portion of the pinned pattern adjacent tothe tunnel barrier pattern and the magnetization direction of thestorage free pattern in the opposite directions.
 4. The device of claim1, wherein the storage free pattern is thicker than the guide freepattern.
 5. The device of claim 1, the pinned pattern comprises: a firstmagnetic pattern; a second magnetic pattern; and a pinned reversingpattern between the first and second magnetic patterns, the pinnedreversing pattern configured to reverse magnetization directions of thefirst and second magnetic patterns in the opposite directions, whereinthe first magnetic pattern contacts the invariable pinning pattern sothat a magnetization direction thereof is pinned by the invariablepinning pattern, and a magnetization direction of the second magneticpattern is pinned by the pinned reversing pattern in an oppositedirection to the pinned magnetization direction of the first magneticpattern, and the second magnetic pattern contacts the tunnel barrierpattern.
 6. The device of claim 1, wherein the invariable pinningpattern, the pinned pattern, the tunnel barrier pattern, the storagefree pattern, the free reversing pattern, the guide free pattern, andthe variable pinning pattern are sequentially stacked on the substrate.7. The device of claim 1, the variable pinning pattern, the guide freepattern, the free reversing pattern, the storage free pattern, thetunnel barrier pattern, the pinned pattern, and the invariable pinningpattern are sequentially stacked on the substrate.
 8. The device ofclaim 1 further comprising: a bit line on the substrate; a lowerelectrode between the substrate and the invariable pinning pattern; andan upper electrode between the variable pinning pattern and the bitline, wherein sidewalls of the high resistance pattern, the lowerelectrode, the upper electrode, the invariable pinning pattern, thevariable pinning pattern, and the free reversing pattern aresubstantially aligned with each other.
 9. The device of claim 1, whereinthe variable pinning pattern is between the invariable pinning patternand the substrate.
 10. The device of claim 2, wherein a maximumtemperature at which a magnetization pinning force of the invariablepinning pattern is maintained is higher than a maximum temperature atwhich a magnetization pinning force of the variable pinning pattern ismaintained.
 11. The device of claim 10, wherein the invariable pinningpattern includes a first antiferromagnetic substance, and the variablepinning pattern includes a second antiferromagnetic substance having ablocking temperature lower than that of the first antiferromagneticsubstance; and wherein the blocking temperature is a maximum temperatureat which an exchange coupling force of an antiferromagnetic substance ismaintained, and the exchange coupling force corresponds to themagnetization pinning force.
 12. The device of claim 10, wherein theinvariable pinning pattern and the variable pinning pattern include anantiferromagnetic substance, the invariable pinning pattern beingthicker than the variable pinning pattern.
 13. The device of claim 8further comprising an upper contact plug between the upper electrode andthe bit line and a lower contact plug between the substrate and thelower electrode.
 14. The device of claim 8, wherein the high resistancepattern is between the variable pinning pattern and the lower electrode.15. A magnetic memory device comprising: an invariable pinning pattern,a variable pinning pattern, and a bit line on a substrate; a lowerelectrode between the substrate and the invariable pinning pattern; anupper electrode between the variable pinning pattern and the bit line; atunnel barrier pattern between the invariable pinning pattern and thevariable pinning pattern; a pinned pattern between the invariablepinning pattern and the tunnel barrier pattern, the pinned patternconfigured to have a magnetization direction pinned by the invariablepinning pattern; a storage free pattern between the tunnel barrierpattern and the variable pinning pattern; a guide free pattern betweenthe storage free pattern and the variable pinning pattern; and a freereversing pattern between the storage and guide free patterns, sidewallsof the free reversing pattern, the lower electrode, the upper electrode,the invariable pinning pattern, and the variable pinning pattern beingsubstantially aligned with each other, the free reversing pattern beingconfigured to reverse a magnetization direction of the storage freepattern and a magnetization direction of the guide free pattern inopposite directions.
 16. A magnetic memory device comprising: aninvariable pinning pattern and a variable pinning pattern on asubstrate, the variable pinning pattern between the invariable pinningpattern and the substrate, the invariable pinning pattern including afirst antiferromagnetic substance, and the variable pinning patternincluding a second antiferromagnetic substance having an elementdifferent from that of the first antiferromagnetic substance; a tunnelbarrier pattern between the invariable pinning pattern and the variablepinning pattern; a pinned pattern between the invariable pinning patternand the tunnel barrier pattern, the pinned pattern configured to have amagnetization direction pinned by the invariable pinning pattern; astorage free pattern between the tunnel barrier pattern and the variablepinning pattern; a guide free pattern between the storage free patternand the variable pinning pattern; and a free reversing pattern betweenthe storage and guide free patterns, the free reversing pattern beingconfigured to reverse a magnetization direction of the storage freepattern and a magnetization direction of the guide free pattern inopposite directions.
 17. The device of claim 16, wherein the variablepinning pattern has a first surface contacting the guide free patternand a second surface opposite the first surface, the device furthercomprising a high resistance pattern contacting the second surface ofthe variable pinning pattern and including oxygen and elements includedin the variable pinning pattern.
 18. The device of claim 16 furthercomprising: a bit line on the substrate; a lower electrode between thesubstrate and the variable pinning pattern; and an upper electrodebetween the invariable pinning pattern and the bit line, whereinsidewalls of the lower electrode, the upper electrode, the invariablepinning pattern, the variable pinning pattern, the tunnel barrierpattern, the storage free pattern, the guide free pattern, the freereversing pattern, and the pinned pattern are substantially aligned witheach other.
 19. The device of claim 18 further comprising an uppercontact plug between the upper electrode and the bit line and a lowercontact plug between the substrate and the lower electrode.